以太坊入门之搭建truffle框架（一）

一、truffle介绍

Truffle 是最流行的开发框架，能够在本地编译、部署智能合约，使命是让开发更容易。

Truffle 需要以太坊客户端支持，需要支持标准的JSON RPC API。

有许多的以太坊客户端可以选择。我们推荐在开发和部署时使用不同客户端。

适用开发的客户端

• EtherumJS TestRPC

适用正式发布的客户端

• Geth (go-ethereum)

当开发基于 Truffle 的应用时，推荐使用EthereumJS TestRPC。它是一个完整的在内存中的区块链仅仅存在于你开发的设备上。相对于 Geth，TestRPC 它在执行交易时是实时返回，而不等待默认的出块时间，这样你可以快速验证你新写的代码，当出现错误时，也能即时反馈给你。它同时还是一个支持自动化测试的功能强大的客户端。Truffle充分利用它的特性，能将测试运行时间提速近90%。

truffle官方文档：http://truffleframework.com/docs/getting_started/installation

二、下载truffle并初步建立demo项目

#npm install -g truffle
#mkdir truffle-app1
#truffle unbox metacoin  //会下载并初始化项目
Downloading...
Unpacking...
Setting up...
Unbox successful. Sweet!

Commands:

  Compile contracts: truffle compile
  Migrate contracts: truffle migrate
  Test contracts:    truffle test

# ls
contracts  migrations  test  truffle-config.js  truffle.js
# truffle compile  //编译项目
Compiling ./contracts/ConvertLib.sol...
Compiling ./contracts/MetaCoin.sol...
Compiling ./contracts/Migrations.sol...

Compilation warnings encountered:

/opt/go-ethereum/ethereum/truffle-app3/contracts/MetaCoin.sol:15:2: Warning: Defining constructors as     functions with the same name as the contract is deprecated. Use "constructor(...) { ... }" instead.
    function MetaCoin() public {
 ^ (Relevant source part starts here and spans across multiple lines).
,/opt/go-ethereum/ethereum/truffle-app3/contracts/Migrations.sol:11:3: Warning: Defining constructors as     functions with the same name as the contract is deprecated. Use "constructor(...) { ... }" instead.
  function Migrations() public {
 ^ (Relevant source part starts here and spans across multiple lines).
,/opt/go-ethereum/ethereum/truffle-app3/contracts/MetaCoin.sol:23:3: Warning: Invoking events without     "emit" prefix is deprecated.
            Transfer(msg.sender, receiver, amount);
            ^------------------------------------^

Writing artifacts to ./build/contracts

# ls
build  contracts  migrations  test  truffle-config.js  truffle.js
[root@feijian truffle-app3]# cd build/contracts/
[root@feijian contracts]# ls  //我们能看到这个目录下就是编译生成的合约json文件
ConvertLib.json  MetaCoin.json  Migrations.json